Tasmania's rare 'walking' fish returned to wild following rescue

Scientists from the Institute for Marine and Antarctic Studies (IMAS) collected 25 red handfish in January and cared for them in captivity.

During this time, they worked to remove native urchins in the red handfish habitat who overgrazed the seaweed and seagrass handfish rely on for their survival.

There are an estimated 50 to 100 red handfish left in the wild.

Marine ecologist Jemina Stuart-Smith, who co-leads the red handfish research and conservation program at IMAS, said the red handfish faced many threats.

"With their extremely limited population and a severely degraded habitat, we considered the additional threat of high temperature was a possible extinction risk," she said.

The rescue followed advice from an emergency workshop hosted by the Australian government's Department of Climate Change, Energy, the Environment and Water, with support from the state government.

Dr Stuart-Smith said removing the handfish had been a difficult decision.

"However, the site data shows the temperatures this summer exceeded previous known maximums," Dr Stuart-Smith said.

"We can only assume that this additional stressor would have impacted the already vulnerable population - so despite the risk, it appears to have been the right approach."

Conservation breeding project lead for red handfish at IMAS, Andrew Trotter, said the team were happy to care for the fish, but glad to see their return.

"They're wild animals and belong in the sea," he said.

"We returned 18 red handfish to the wild, keeping four fish to include in the captive breeding program at IMAS for at least this year, to help improve the genetic diversity of the population.

He said while they expected some deaths in captivity, they were disappointed to see three fish die.

"But this has highlighted the urgent need to better understand disease in this species," Dr Trotter said.

IMAS scientist will continue to monitor red handfish in the wild, while the captive breeding program will allow the return of more individuals to wild populations in the future.

Dr Stuart-Smith said the rescue effort showed they could rapidly implement adaptive management stratigies for critically endangered species.

"We're now focused on habitat restoration and management at red handfish sites which is crucial to the survival of the species," she said.